In a typical water or gas service installation, the main water or gas line is connected to a corporation valve adjacent the main line and through a service valve to a residential water or gas system. The service valve is located under a curb or sidewalk and a valve box extends from the service valve to the surface, so that the surface valve can be turned "on" and "off" by means of an elongated wrench or a key. The valve box may appear at the surface either at the sidewalk or at the roadway, but in either case it must be flush with the surface. Thus, the length of the valve box must be carefully adjusted not only during the initial installation, but also each time a new layer of material is added to the surface around the top of the valve box.
During the initial installation of a valve box, a two-piece, telescoping assembly is usually provided to permit adjustments to compensate for variations in depth between the valve and the surface. Since the telescoping action occurs well below the surface, further adjustment is usually impossible after the initial installation has been made. The telescoping valve box may be of the slip-type in which one member is slidably mounted within the other and in which means is provided to lock the members together after a desired length is achieved. The telescoping valve box may also be of the screw-type in which one member is threaded onto the other.
During resurfacing operations of the street or sidewalk, the new surfce may very often lie above the top of the valve box. In such case, the top of the valve box is brought up to the level of the new surface by inserting an adapter into the top of the existing valve box, thereby increasing its overall length. These adapters have traditionally been of fixed length and available in one inch increments. Therefore, it is necessary to have available an assortment of adapters in one inch increments. Very often, the height needed to bring the top of the valve box flush with the new surface lies between two increments. In colder climates, during the winter season, ground frost may cause the valve box assembly to rise above ground level and it may remain in that position after the spring thaw. When this occurs it is necessary to excavate the valve box assembly and lower it to its original position. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is therefore, an outstanding object of the invention to provide a valve box assembly which is adjustable in height during and after installation.
Another object of this invention is the provision of a valve box assembly in which fine height adjustment can be made.
A further object of the present invention is the provision of a valve box which is adjustable for tilt angle to accomodate a sloping surface.
It is another object of the instant invention to provide a valve box assembly which can be adjusted with a minimum amount of digging or excavation.
A still further object of the invention is the provision of a valve box assembly which includes a riser mounted within a valve box for fine height adjustment, a cover for closing the top of the riser and means for providing a seal between the cover and riser.
It is a further object of the invention to provide an adapter for existing valve boxes, which adapter provides for fine height adjustment of the valve box.
It is a further object of the invention to provide an adapter for existing valve boxes which is adjustable for tilt angle to accomodate a sloping surface.
It is a further object of the invention to provide an adapter for existing valve boxes which can be installed and adjusted with a minimum amount of digging.
Another object of the invention is to provide an adapter having a riser and adjusting nut for supporting the riser at the top of an existing valve box.
A further object of the present invention is the provision of an adapter having a riser adapted to receive an existing valve box cover.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.